'The injured Mason', 1786-1787 (1939). Two workers carry another, who has been wounded in a work accident. The scaffolding in the background reveals the underlying subject as workers´ safety. The painting is held at the Museo del Prado, Madrid. From Les Chefs-D'Ouevre Du Musée Du Prado. [Les Éditions Holbein, Switzerland, 1939]